Method and apparatus for removing objects and material from wells



Sapt. 10, 1940. J. a. STOVALL 2,214,238

METHOD AND APPARATUS FOR REMOVING OBJECTS AND MATERIAL FROM WELLS 2 Sheets-Sheet 2 Filed Sept. 17, 1938 Patented Sept. 10, 1940 OBJECTS AND MATE James B. Stcvall, Whittier,

RIALFROM WELLS Calif., assignor to Globe Oil Tools Company, Los Nietos, Calii'., a corporation of California Application September 1-7, 1938, Serial No. 230,452

. 7 Claims. This invention relates to the art of well drilling and relates more particularly to' a method .and means for removing objects and material from deep wells such as oil wells and gas wells. A general object of this invention is to provide a simple, emcient method and a practical, effective apparatus for removing objects and material from wells. V I

In the drilling of wells such as oil wells and gas wells, tools and parts of tools are often lost in the well. These lost parts greatly interfere with the drilling operations and it is usually necessary to remove them from the well. various types have been employed to recover such lost objects. The conventional fishing tools are usually quite successful in the recovery of large objects but often are not practical or operative for the recovery of small objects. For example, basket bits of the general class disclosed in Patent No. 2,054,278, granted to J. C. Wright and J. H. Howard, have proved quite successful, especially in the recovery of large objects, but are not entirely successful when it is necessary'to remove small objects such as ball bearings, cutter supporting pins, slivers of steel, etc. from the wells. Bailers of the vacuum type or hydrostatic type are sometimes employed to remove fish and unwanted materials from wells but there is a considerable hazard in the use of such bailers.

Another object of this invention is to provide a rapid inexpensive method for removing small objects such as bearing parts, particles of metal, etc. from deep wells. 4

Another object of this invention is to provide a rapid, safe and efficient method for drawing or removing parafiin, mud and similar materials from the earth formation in a well to restore or increase the production of the well.

Another object of this invention is to provide a method of the character mentioned in which the hydrostatic pressure of the column of liquid standing in the well is utilized to force or move the lost objects or tool parts as well as mud, paraflin, etc. into the fishingtool and fishing string to be trapped therein.

Another object of this invention is to provide a fishing method of the character mentioned in which a sudden rush of fluid for carrying the lost objects into the fishing tool and string is initiated or produced by a simple operation at the top of the well without the necessity of disturbing the fishing string or the drilling equipment.

Another object of this invention is to provide a Fishing tools of simple, readily controlled means for producing or causing a sudden rush of fluid from the bottom of the well into the fishing tool and string to carry the lost objects and unwanted materials from the well into the fishing tool and the fishing string.

Another object of this invention is to provide a novel valve for embodiment in the-operating string of a basket bit that is operableto provide for the movement or propulsion of lost objects into the bit by a sudden inrush of liquid in the bit.

Another object of this invention is to provide apparatus of the character mentioned embod-ying simple, yet efiective means for controlling the valve in the operating string or fishing string.

A further object of this invention is to provide a valve of the character mentioned that allows a free flow of fluid through the operating string in both directions following the opening of the valve. The valve embodied in the apparatus of the present invention resembles a so-called float valve in that it initially prevents an upward flow of fluid in the drilling string or operating string but differs radically from a typical float valve in that it allows a free flow of fluid both upwardly or downwardly in the string following its release or operation.

The various objects and features of my invention will be fully understood from the followof apparatus and manner of carrying out the.

method of my invention, throughout which description reference is made to the accompanying drawings; in which:

Fig. 1 is a side elevation of the fishing apparatus provided by the present invention. Fig. 2

is an enlarged, longitudinal,. detailed sectional view of the basket bit.

Fig. 3 is an enlarged, longitudinal, detailed sectional view of the valve connected in the operating string, illustrating the ball in the closed position. Fig. 4 is an enlarged, longitudinal, detailed sectional view of the means for releasing the go-devil or valve opening member. Fig. 5 is an enlarged, frag-' mentary, longitudinal, detailed sectional view of the valve shown in Fig. 3, illustrating the ball in the open position. Fig. 61s an enlarged transverse detailed sectional view taken as indicated by line 6-6 on Fig. 3. Fig. 7 is a side elevation of the'go-devil or valve opening mem-.

her, and Fig. 8 is a vertical sectional view of a frangible closure means that may be embodied in the apparatus.

'It is believed that the method of the present invention will be better understood following a description of the apparatus. Accordingly, I will proceed with a detailed description of a typical preferred form of apparatus of the invention. The apparatus provided by this invention may be said to comprise, generally, a tubular fishing string or operating string S, a basket bit- H) on the lower end of the strim S operable to trap objects and to recover a core, a valve interposed in the operating-string S operable to control the entrance or fiow of fluid from the well into the bit l0 and string S and means l2 for controlling or opening the valve The operating string S is provided to carry and operate the bit lo and to handle the well fiuid under the control of the valve II. In practice the operating string S may be in the nature of a rotary well drilling'string made up of lengths of drill pipe connected by collars andtool joints in the usual manner. It is to be understood that the string S is sufliciently long to extend from the ground surface to the bit III at the bottom of the well. The string S is adapted to be handled by the hoisting and rotary equipment in the well derrick. A polygonal kelly or drill stem I3 is connected with the upper end of the string S in the manner to'be subsequently described for the purpose of transmitting rotation to the string.

The bit vill is secured to the lower end of the operating string S and is operable to receive and retain objects that may be lost in the well, to receive and retain unwanted material from the well and to cut and retain a core of earth formation. The bit I0 is a tubular assembly and includes a tubular barrel or body l4. The bit body I4 is provided at its upper end with a reduced portion l5 having asocket |6 for receiving the threaded pin of a tool joint section IT. A bit head I8 is secured to the lower end of the body l4. In practice the head |8 may be threaded on the lower end part of the body H in such a manner that thelower end of the body forms a downwardly facing shoulder in the head. Cutting parts are provided on the head l8 to make an annular cut in the earth formation and thus form a core. In the case illustrated the cutting means of the bit Ill comprises a multiplicity of circumferentially spaced blades l9 projecting downwardly and outwardly from the lower end of the head 18. The inner lower corners ofthe blades l9 are bevelled upwardly and inwardly to assist in directing the fish or lost objects into the bit ID, as will be more fully described. An upwardly facing internal shoulder 20 is provided in the head l8 some distance below the lower end of the body l4.

In accordance with the invention the bit I0 is provided with means for retaining and trapping the core of earth formation and the objects to be recovered from the well. In the preferred construction there are two vertically spaced fish and core trapping or retaining means in the head l8 of the bit Hi. The lowermost fish and. core trapping means includes a ring 2| arranged in the bit head I8 and adapted to rest on the shoulder 20. The ring 2| may be free to rotate at will. A series of circum'ferentially spaced windows 22 is provided inithe ring 2|. Pins 23 pivotally support dogs 24 in the windows 22. The dogs 24 are adapted to project inwardly in the ring 2| to grip or support thecore of earth formation and to trap or retain the obj cts recovered from the well. Torsional springs 25 are wrapped about the pins 23 to yieldingly urge the dogs 24 downwardly and inwardly to the positlons illustrated in Fig. 2 of the drawings. The dogs 24 are preferably quite long to project inwardly to adjacent the central vertical axis of the ring 2| when in their fully projected positions. The dogs 24 are preferably bevelled or shaped to have pointed or sharp inner ends and to present substantially fiat horizontal upper sides when in the fully projected positions. It is preferred to space the dogs 24 close together to be effective in trapping small objects and to effectively retain and support cores of soft earth formation and broken or shattered cores.

The upper fish and core retaining means in- .cludes a ring 26 arranged within the bit head l8 between the upper end of the ring 2| and the 29 and yieldingly urge the dogs 28 downwardly and inwardly to the positions illustrated in Fig. 2 of the drawings. The dogs 28 are somewhat shorter than the dogs 24' and are bevelled or sharpened to-bite into and support cores of firm or hard earth formations. The dogs 28 are in close relation to effectively trap and retain objects when in the core supporting positions.

The valve H is an important element of the apparatus. The valve II is provided to close the tubular string S against the upward movement of fiuid when the string is runinto the well and thus prevent or limit the entrance of well fluid into the lower end of the string. The valve II is adapted to be opened by the means l2 to allow the fluid under the high hydrostatic pressure in the well to suddenly rush upwardly through the bit I0 and into the lower portion of the string S to carry the lost objects and/or the unwanted materials from the well into the bit andstring. The valve II is connected or interposed in the operating string S at a point between its ends. It is preferredto connect the valve II in the upper portion of the string S so that the liquid level in the well is not lowered to such an extent as to cause caving of the well when the valve is opened to admit the fluid to the string S.

The valve further includes a ball 42 adapted to seal upwardly against the seat 31. The ball 42 is arranged in the upper opening 33'of the cage 36 and is operable to engage the seat 31 to prevent the upward fiow of fluid in the passage P of the string S. Yieldable or releasable means is provided for holding the ball 42 against the seat 31. This means comprises a plurality of spaced leaf springs 43 attached to the wall of the opening 38 by pins or rivets. The springs 43 project upwardly and inwardly to cooperate with the ball 42. The projecting portions of the springs 43 are curved or bent upwardly and inwardly and then upwardly and outwardly to provide the springs with inwardly and downwardly facing surfaces 44 and upwardly and inwardly facing surfaces 46. The surfaces 45 of the springs 43 initially or normally bear upwardly against the under side of the ball 42 to hold the ball in effective sealing engagement with the seat 31. The springs 43 are yieldable when the ball 42 is forcibly movedv 2,314,288 It is important to note that the springs 43 are operable to hold the ball 42in an open or down position where the passage 4| is clear or open to pass fluid between the openings 38 and 38'and to allow for the free flow of fluid through the passage P of the string S in either dire of the drawings shows the ball 42 in its open position.

The means l2 for opening the valve I I includes a go-devil or member 48 adapted to be pumped or dropped down through the passage P of the string S from the upper portion of the string to strike the ball 42 and force it down to its open position. The valve opening member 46 may be ir. the nature of a long stem or rodproportioned to pass through the passage P with substantial clearance. Sets of vetrically spaced guide ribs or fins 41 are provided on the member 46 for guiding the member and holding it centralized in the passage P. Themember 48 is proportioned to pass down through the valve seat 31 so that its Joint sections 49 and .50 of preferred to provide the body lower end may strike the upper side of the ball 42 to forcibly move the ball to its open position;

In accordance with the broaderaspects ofthe invention any suitable means may be employed to introduce the valve opening member 46 to the passage P of the string S. The means I2 illustrated in the drawings includes a novel and effective means for releasing the'member 46 for downward movement through the passage P or for forcing the member down through the passage. This means includes a connecting member or tubular body 48 interposed in the string S. The body 48 may be connected between two tool the string S. It is 48 in the upper portion of the string S. In the case illustrated in the drawings the tool joint section 49 at the upper end of the body 48 connects the body with the lower end of the drill stem l 3.

The body 48 is tubular having a central longitudinal opening 5| forming a part or continua tion of the passage P. Ari-annular inwardly projecting flange 52 is provided on the wall of the opening 5| between the ends of the body 48. The valve opening member 46 is adapted to be positioned with its upper part extending through and beyond the flange 52. Releasable means is provided for holding the member 46 in this position. An annular groove 53 is provided in the upper part of the member 46 and a frangible pin or shear pin 54 is arranged, through a lateral opening 55 in the body 48 to have its inner part project into the groove 53. The pin .54 engaging in the groove 53 initially or normally-holds .the

valve opening in Fig. 4.

It is preferred to about the member 48 when the member is supported by the shear pin 54. An annular'body of packing 58 is arranged in the opening 5| and rests on the upper side of the flange 52. The packing 58 engages and seals about the upper part of the member 46. A- tubular nut 51 is member 46 in the position shown threaded in the opening 5| to engage against the upper side of'the packing 56 to retain the packing ction. Fig. 5

provide means for packing 3 valve opening member 48 is secured in the body .48 by means of the pin 54 when the string is made up. When the string has been lowered to a position where the bit l8 engages the bottom of the well the string is raised a short distance to lift the bit clear of the bottom wall of the well. The ball 42 of the valve II is in its closed posi-. tion when the string is made up and run in the well, The ball 42 cooperating with the seat 31 prevents an upward flow of fluid through the passage P of the string S with the result that the well liquid is excluded from the string except that portion of fluid that will occupy the space or volume in the string resulting from the compression of the air trapped in the string. 1

When the bit "I has been lifted a short distance from the bottom of the well, as described above, the valve opening member 48 is released or forced downwardly to open the valve II. To release the valve opening member 46 the pump or pumps handling the circulation fluid are started to pump liquid under pressure into the'drill stem I3. This fluid pressure acts on the upper end of the member 46 and when a sufilcient pressure has been built up in the drill stem l3 and the tool joint-section the pin 54 breaks and the builtup pressure acting on the upper end of the member 48 forces the member down through the passage P of the string S. The member 46 falls or moves down through the passage P until its lower end strikes the ball 42. The member 46 forces the ball 42.down through the springs 43 to the lower end of the opening 38 in swhich position static pressure in the well carries with it the lost objects and the unwanted mud or other materials so thatthe same are received in the bit i0 and the string S. The liquid rushing into the bit Ill operates to carry with it large objects as well as the smaller lost objects. The sudden in-rush of fluid into the bit l0 and string S may be effective in pulling paraflin and other materials from the earth formation and the apparatus is useful in cleaning and reconditioning wells to increase their production. When the hydrostatic pressures in the interior and the exterior of the string S have become balanced following the opening of the valve I I the string Sis lowered to engage the bit H) with the bottom of the well and the string is then rotated and fed downwardly. The blades 19 of the bit III are operable to cut an annular channel in the earth formation at the bottom of the well and form a core as the bit is rotated and fed downwardly. This core entering or received in the bit l0 operates ,to' support'or carry with it the fish or lost objects that have previously entered the 'bit and forms an effective plugfor preventing the escape of the trapped objects and unwanted materials obtained from. the well.

The drilling or core cutting operation may continue until a core of substantiallength has been formed. The string S is then raised or moved upwardly. Upon upward movement of the bit l8 the dogs 24 or 28, or both, pivot downwardly'and inwardly to their fully projected'positions. The

,dogs 24 and when projected are operable to cut or break the corefree from the earth formation as the bit I8 is raised. The dogs 24 and 28 also serve to trap and retain the small fish or lost objects and to support the core in the bit I0.

As described above, the dogs 24 and 28 are in close relation to dependably support and retain the core and to prevent the loss of the lost objects from the bit It. The string S is removed from the well following the obtaining of the core,

and the core, lost objects and material obtained lustrated, this frangible closure means includes a tube 60 adapted to be inserted in the abovedescribed body 3|. The tube 60 may rest on the shoulder and its upper end is engaged by the 4 nut or seat 31 whereby the seat holds the tube in place. An upwardly facing internal shoulder BI is provided in the tube 60 and a frangible disc 62 rests on the shoulder. The disc 62 extends across the interior of the tube to close the tube against the flow of fluid therethrough. A tubular nut 63 is threaded in the upper portion of the tube 60 to hold the disc 62 on its shoulder 6|.

In'the use or operation of the apparatus embodying the closure means illustrated in Fig. 8 the disc 62 normally or initially prevents the upflow or fluid in the string S. When the string .3 has been lowered to the correct position in the well and it is desired to provide for the sudden inrush of fluid to the string the go-devil or member 46 is dropped or pumped down the string, as described above. The lower end of the member 46 strikes the frangible disc 62 and breaks the same. This results in a sudden in-rush of fluid into the bit It! and the string S, and the fluid carries with it the fish and unwanted material from the well. The vanes 41 are adapted to engage the' seat 37 to limit the downward travel of the member 56 so that the member does not fall through the string S to the bit I10.

Having described only typical preferred forms of apparatus and manners of carrying outthe method of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations er modifications that may appear to those skilledin the art or fall within the scope of the following claims:

Having described my invention, I claim:

1. Apparatus of the character described comprising a string of well pipe, a tubular body connected in the string, a seat in the body, ashiftable ball valve engageable with the seat to prevent the flow of fluid through the string in one direction and movable to a position where the fluid may flow through the string in either direction, and spring flngers releasably holding the valve against the seat and operable to retain the valve in the position where fluid may flow in either direction.

2.- Apparatus of the character described comprising a string of well pipe, a tubular body connected in the string, a seat in the body, a shiftable valve engageable with the seat to prevent the flow of fluid through the string in one direction and movable to a position where the fluid may flow through the string in either direction, leaf springs in the body releasably holding the valve in engagement with the seat and operable to hold the,valve in an open position where the fluid may flow in either direction through the string, and means for moving the valve to the said open position.

3. Apparatus of the character described comprising a string of well pipe, a tubular body conheated in the string, a seat in the body, a shiftable valve engageable with the seat to prevent the flow of fluid through the string in one direction "and movable to a position where the fluid may flow through the string in either direction,

a series of spaced spring fingers in the body releasably holding the valve in engagement with the seat and operable to hold the valve in an open position where the fluid may flow in either direction through the string, and means for moving the valve to the said open position, the last mentioned means including a member movable downwardly through the string to strike the valve.

4. Apparatus for removing material from a well comprising a string of well pipe extending from the bottom of the well to the top of the well, a core taking bit on the lower end of'the string, a frangible closure provided in the upper portion of the string to prevent the upflow of fluid therethrough, and means for breaking the closure to allowthe well liquid to rush into the bit to carry said material therein, said means including a member movable down the string to strike the closure, and releasable means above the closure initially holding the member against movement.

5. Apparatus for removing objects from a well comprising a string of well pipe, a core taking bit on the lower end of the string, a valve provided in the string to prevent the upflow of fluid therethrough, and means for opening the valve to allow the well liquid to rush into the bit to carry said object therein, said means including a member movable down the string to engage the valve, and releasable means initially holding the member against movement above the valve, including a shear pin holding the member in position where it closes the string so that fluid pres-, sure in the string above the member may act on the member to break the pin.

6. In apparatus of the character described for use with a tubular well string, a downwardly facing valve seat in the string, a ported cage in the string adjacent the seat, a movable valve closure, and spring fingers on the cage normally holding the closure against the seat ,to prevent an upflow throughthe string yieldable upon the application of a given down force on the closure to allow downward movement of the closure away from the seat, the spring fingers including parts for gripping the closure following said downward movement to hold the closure against movement in the cage.

'7. In apparatus of the character described for use-with a tubular well string, a tubular body to be interposed in the string, a downwardly facing valve seat in the body, a ported cage in the body under the seat, a ball for sealing upwardly against the seat, spaced spring fingers on the cage, parts on the fingers for initially holding the ball up against the seat, the fingers being yieldable under a down force on the ball to allow downward movement of the ball from the seat to a position in the cage, and parts on the spring fingers for retaining the ball in said position in the cage so that fluid may flow through the string in either direction. 7

' JAMESB. STOVALL. 

